QGIS API Documentation 3.29.0-Master (53715c36dc)
qgsnetworkcontentfetcherregistry.cpp
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1/***************************************************************************
2 qgsnetworkcontentfetcherregistry.cpp
3 -------------------
4 begin : April, 2018
5 copyright : (C) 2018 by Denis Rouzaud
7
8 ***************************************************************************/
9
10/***************************************************************************
11 * *
12 * This program is free software; you can redistribute it and/or modify *
13 * it under the terms of the GNU General Public License as published by *
14 * the Free Software Foundation; either version 2 of the License, or *
15 * (at your option) any later version. *
16 * *
17 ***************************************************************************/
18
20
21#include "qgsapplication.h"
22#include <QUrl>
23#include <QFileInfo>
24#include <QDir>
25
27{
28 QMap<QString, QgsFetchedContent *>::const_iterator it = mFileRegistry.constBegin();
29 for ( ; it != mFileRegistry.constEnd(); ++it )
30 {
31 delete it.value();
32 }
33 mFileRegistry.clear();
34}
35
36QgsFetchedContent *QgsNetworkContentFetcherRegistry::fetch( const QString &url, const Qgis::ActionStart fetchingMode, const QString &authConfig )
37{
38
39 if ( mFileRegistry.contains( url ) )
40 {
41 return mFileRegistry.value( url );
42 }
43
44 QgsFetchedContent *content = new QgsFetchedContent( url, nullptr, QgsFetchedContent::NotStarted, authConfig );
45
46 mFileRegistry.insert( url, content );
47
48 if ( fetchingMode == Qgis::ActionStart::Immediate )
49 content->download();
50
51
52 return content;
53}
54
55QFile *QgsNetworkContentFetcherRegistry::localFile( const QString &filePathOrUrl )
56{
57 QFile *file = nullptr;
58 const QString path = filePathOrUrl;
59
60 if ( !QUrl::fromUserInput( filePathOrUrl ).isLocalFile() )
61 {
62 if ( mFileRegistry.contains( path ) )
63 {
64 const QgsFetchedContent *content = mFileRegistry.value( path );
65 if ( content && content->status() == QgsFetchedContent::Finished && content->file() )
66 {
67 file = content->file();
68 }
69 else
70 {
71 // if the file is not downloaded yet or has failed, return nullptr
72 }
73 }
74 else
75 {
76 // if registry doesn't contain the URL, return nullptr
77 }
78 }
79 else
80 {
81 file = new QFile( filePathOrUrl );
82 }
83 return file;
84}
85
86QString QgsNetworkContentFetcherRegistry::localPath( const QString &filePathOrUrl )
87{
88 QString path = filePathOrUrl;
89
90 if ( !QUrl::fromUserInput( filePathOrUrl ).isLocalFile() )
91 {
92 if ( mFileRegistry.contains( path ) )
93 {
94 const QgsFetchedContent *content = mFileRegistry.value( path );
95 if ( content->status() == QgsFetchedContent::Finished && !content->filePath().isEmpty() )
96 {
97 path = content->filePath();
98 }
99 else
100 {
101 // if the file is not downloaded yet or has failed, return empty string
102 path = QString();
103 }
104 }
105 else
106 {
107 // if registry doesn't contain the URL, keep path unchanged
108 }
109 }
110 return path;
111}
112
113
114
115
116void QgsFetchedContent::download( bool redownload )
117{
118
119 if ( redownload && status() == QgsFetchedContent::Downloading )
120 {
121 {
122 if ( mFetchingTask )
123 disconnect( mFetchingTask, &QgsNetworkContentFetcherTask::taskCompleted, this, &QgsFetchedContent::taskCompleted );
124 }
125 cancel();
126 }
127 if ( redownload ||
130 {
131 mFetchingTask = new QgsNetworkContentFetcherTask( mUrl, mAuthConfig );
132 // use taskCompleted which is main thread rather than fetched signal in worker thread
133 connect( mFetchingTask, &QgsNetworkContentFetcherTask::taskCompleted, this, &QgsFetchedContent::taskCompleted );
134 connect( mFetchingTask, &QgsNetworkContentFetcherTask::taskTerminated, this, &QgsFetchedContent::taskCompleted );
136 QgsApplication::taskManager()->addTask( mFetchingTask );
138 }
139
140}
141
143{
144 if ( mFetchingTask && mFetchingTask->canCancel() )
145 {
146 mFetchingTask->cancel();
147 }
148 if ( mFile )
149 {
150 mFile->deleteLater();
151 mFilePath = QString();
152 }
153}
154
155
156void QgsFetchedContent::taskCompleted()
157{
158 if ( !mFetchingTask || !mFetchingTask->reply() )
159 {
160 // if no reply, it has been canceled
162 mError = QNetworkReply::OperationCanceledError;
163 mFilePath = QString();
164 }
165 else
166 {
167 QNetworkReply *reply = mFetchingTask->reply();
168 if ( reply->error() == QNetworkReply::NoError )
169 {
170 // keep extension, it can be useful when guessing file content
171 // (when loading this file in a Qt WebView for instance)
172 const QString extension = QFileInfo( reply->request().url().fileName() ).completeSuffix();
173
174 QTemporaryFile *tf = new QTemporaryFile( extension.isEmpty() ? QString( "XXXXXX" ) :
175 QString( "%1/XXXXXX.%2" ).arg( QDir::tempPath(), extension ) );
176 mFile = tf;
177 tf->open();
178 mFile->write( reply->readAll() );
179 // Qt docs notes that on some system if fileName is not called before close, file might get deleted
180 mFilePath = tf->fileName();
181 tf->close();
183 }
184 else
185 {
187 mError = reply->error();
188 mFilePath = QString();
189 }
190 }
191
192 emit fetched();
193}
ActionStart
Enum to determine when an operation would begin.
Definition: qgis.h:522
static QgsTaskManager * taskManager()
Returns the application's task manager, used for managing application wide background task handling.
FetchedContent holds useful information about a network content being fetched.
QFile * file() const
Returns a pointer to the local file, or nullptr if the file is not accessible yet.
ContentStatus status() const
Returns the status of the download.
void download(bool redownload=false)
Start the download.
const QString filePath() const
Returns the path to the local file, an empty string if the file is not accessible yet.
void errorOccurred(QNetworkReply::NetworkError code, const QString &errorMsg)
Emitted when an error with code error occurred while processing the request errorMsg is a textual des...
@ Finished
Download finished and successful.
@ NotStarted
No download started for such URL.
@ Downloading
Currently downloading.
void fetched()
Emitted when the file is fetched and accessible.
void cancel()
Cancel the download operation.
QString localPath(const QString &filePathOrUrl)
Returns the path to a local file or to a temporary file previously fetched by the registry.
QFile * localFile(const QString &filePathOrUrl)
Returns a QFile from a local file or to a temporary file previously fetched by the registry.
QgsFetchedContent * fetch(const QString &url, Qgis::ActionStart fetchingMode=Qgis::ActionStart::Deferred, const QString &authConfig=QString())
Initialize a download for the given URL.
Handles HTTP network content fetching in a background task.
QNetworkReply * reply()
Returns the network reply.
void cancel() override
Notifies the task that it should terminate.
void errorOccurred(QNetworkReply::NetworkError code, const QString &errorMsg)
Emitted when an error with code error occurred while processing the request errorMsg is a textual des...
long addTask(QgsTask *task, int priority=0)
Adds a task to the manager.
void taskCompleted()
Will be emitted by task to indicate its successful completion.
void taskTerminated()
Will be emitted by task if it has terminated for any reason other then completion (e....
bool canCancel() const
Returns true if the task can be canceled.